当满足条件时，如何在两个网络摄像头(连接到计算机)之间切换？

Question

目前，我正在研究一种针对卧床病人的人脸检测算法。一台摄像机将安装在床边，另一台安装在天花板上。我的想法是在找不到病人的脸时切换相机，这样我就可以知道病人在看什么地方。

我目前的问题就在这里：

if // face not found in first camera
{
    cap.open(1);
    //switch to second camera
}
else 
{
    cap.open(0);
    //continue using first camera
}

我不知道该使用哪个if条件来切换摄像头，这是我的完整代码(包括皮肤检测的代码)

int main() {
    Mat image;

    VideoCapture cap;
    cap.set(CV_CAP_PROP_FRAME_WIDTH, 640);
    cap.set(CV_CAP_PROP_FRAME_HEIGHT, 480);
    cap.open(0);

    //create the cascade classifier object used for the face detection
    CascadeClassifier face_cascade;
    //use the haarcascade_frontalface_alt.xml library
    face_cascade.load("haarcascade_frontalface_alt.xml");

    //setup video capture device and link it to the first capture device
    VideoCapture captureDevice;
    captureDevice.open(0);

    //setup image files used in the capture process
    Mat captureFrame;
    Mat grayscaleFrame;

    //namedWindow("window", 1);
    //create a window to present the results
    namedWindow("outputCapture", 1);

    while (1)
    {

        try
        {
            cap >> image;

            cvtColor(image, grayscaleFrame, CV_BGR2GRAY);
            equalizeHist(grayscaleFrame, grayscaleFrame);


            //convert captured image to gray scale and equalize
            cvtColor(image, grayscaleFrame, CV_BGR2GRAY);
            equalizeHist(grayscaleFrame, grayscaleFrame);

            //create a vector array to store the face found
            std::vector<Rect> faces;

            //find faces and store them in the vector array
            face_cascade.detectMultiScale(grayscaleFrame, faces, 1.1, 3, CV_HAAR_FIND_BIGGEST_OBJECT | CV_HAAR_SCALE_IMAGE, Size(30, 30));

            //draw a rectangle for all found faces in the vector array on the original image
            for (int i = 0; i < faces.size(); i++)
            {
                Point pt1(faces[i].x + faces[i].width, faces[i].y + faces[i].height);
                Point pt2(faces[i].x, faces[i].y);

                rectangle(image, pt1, pt2, cvScalar(0, 255, 0, 0), 1, 8, 0);

                if // face not found in first camera
                {
                    cap.open(1);
                    //switch to second camera
                }
                else {
                    cap.open(0);
                    //continue using first camera
                }
            }

            //print the output
            imshow("outputCapture", image);

            SkinDetector mySkinDetector;

            Mat skinMat;

            cap.read(image);

            //show the current image
            imshow("Original Image", image);

            skinMat = GetSkin(image);

            imshow("Skin Image", skinMat);
        }
        catch (Exception& e)
        {
            const char* err_msg = e.what();
            std::cout << "exception caught: imshow:\n" << err_msg << std::endl;


        }
        waitKey(33);
    }

}

Answer 1

你可以打开两个摄像头(从两个摄像头获取图像)，检查病人的脸在哪里，然后他们关闭一个摄像头。